<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            color: red;
              /*水平对齐
              center
              left
              right
              */
            text-align: left;
            /*
            首行文本缩进
            */
            text-indent:20px ;
            line-height: 50px;
        }
        /*鼠标点击触发*/
        div:active{
            color: red;
            font-size: 30px;
        }
        /* 获取焦点 */


    </style>
</head>
<body>
     <div style="text-decoration:line-through;">this is my text </div>

     <div>设置</div>
</body>
</html>